ASTM D695 Compression Testing of Composites

Standard

Materials

Test Types

In addition to tensile and flexural testing, another common form of determining the material properties of plastic (both unreinforced and reinforced) is compression testing. This test is useful for determining the modulus of elasticity, yield stress, compressive strength, and the deformation beyond yield point. The method by which the compression test shall be conducted is defined in ASTM D695.

Based on testing we have conducted in our lab, we recommend the following equipment for compression testing to ASTM D695: two 50 mm (2 in) diameter hardened-steel compression platens mounted on a tensile testing machine, our compression fixture S4931A, and a strain measuring device such as an AutoX 750 attached directly to the specimen. A strain measurement device is often required for stiff specimens where system compliance can affect test results. Our Bluehill® Universal Materials Testing Software allows you to set the desired test control, automatically calculate the desired results and statistics, and produce a test report.

The standard requires that the specimen is compressively loaded at a rate of 1.3 mm/min until fracture. Prior to testing, you should make sure all specimens are made to the sizes specified in the standard and are free of visible surface flaws. When performing compression testing, we have found that specimen alignment plays an important role in achieving even load distribution, which contributes to the consistency of the results.

We recommend reviewing ASTM D695 to fully understand the test set up, procedure, and results requirements.

The AutoX 750 is a high-resolution, long-travel automatic contacting extensometer. It can be mounted onto any electromechanical 3300, 5500, or 5900 table top and floor model systems, as well as LX, DX, HDX, and KN static hydraulic testing systems. It is well suited for applications involving plastics, metals, biomedical, composites, elastomers, and more. The AutoX has a maximum travel of 750 mm and accuracy of ± 1 µm.

Please choose a subscription optionOne or more required fields are empty, complete the form to continue.One or more fields contain formatting errors, fix the errors to continue.You must agree to Instron's Privacy Policy in order to continue.

“It is our objective at Instron to provide our customers the best ownership experience by delivering the highest quality products, expert support and world-class service.”